#include<stdio.h>
int age(int n)
{
	int f;
	if (n == 1)
		f = 10;
	else
		f = age(n - 1) + 2;
	return f;
}
int main()
{
	int i, j;
	printf("Do you want to know whose age?please input:\n");
	scanf_s("%d", &i);
	j = age(i);
	printf("The %dth person's age is %d\n", i, j);
	return 0;
}